Liner removing device



. July 25, 1939. c. c. BROWN LINER REMovI'NG DEVICE [Illlllll Patented July? z5, 1939 PATENT OFFICE r1.1mm. mnuovnm DEVICE Cicero C. Brown, Houston, Tex.

Application May 18,

'I Claims.

My. invention relates to va, combination tool for removingpipe from wells. It has particular application to the removal of a short length of pipe or strainer set at the lower end of the well into the producing formation. It is quite commonly found that after a pipe or strainer has been set in the weil forsome time the 'perforations in kthe pipe or strainer will become clogged with material making the production so small that the well becomes unproiitable. It then becomes necessaryto withdraw the strainer vor liner from the' well. I

The removal of the pipe is usually a rather diflicult matter due to the `fact that the formavtion has become cemented'around 'the pipe and strainer and can not be readily withdrawn. There` is `also Aa packer at the vupper end of the liner and within the lower end of the casingwhichis set and can not be again contracted.

It is arr-object of my invention to provide a means of removing the pipe'from the Wellincluding cutting the pipeif necessary and then engaging and pulling the cut off portion and 'to further provide in combination with the cutting and pulling device a meansfor clearing out a passage down through the pipeso that the lfluid may drain out therefrom during the pulling operation. o

' It is also an object of the invention to provide an effective type of cutting device which may beA actuated whenever desired by fluid pressure.

'Ihe invention also contemplates the construc- `tio'n of the device vfor gripping and pulling pipe and then again releasing the same.

o In the drawing herewithFig. 1 is a central longitudinal section through a well casing showing afportion of my device therein, said view being partly in elevation.

A -lig. 2 is a similar View showing that-portion of the device below the partv shown linFig. '11;

Fig. 3' is a similar view'ofthe lower end of the device.'

Fig. 4 is of Fig. 2.

I have indicated the well as being equipped with a casing I, the lower end of which is provided with a shoe 2 and cemented at 3 in the well above the producing formation. The well has been eirtended at 4 downwardly into the formation and a j strainer 5 has been set adjacent the formation.

"'Ihestr'ainer 5 is set toward-the lower endl of a gse tionofiineri, the upper endof which is shown Figlas being equipped with a packer 1 of ordinary construction. This packer seals off the a transverse section on the lineL-I so that itis practically frozen inthe well 1936, Serial No. 80,271

(Cl. 16d-0.8)

spacebetween the liner and the interior of the casing so that no liquid can pass through this space. y

The lower end of the strainer 5 is shown as being equipped with a housing 8 for a back pressure valve and other devices ordinarily employed at the lower end of the strainer. This housing has a drag bit 9 at the lower end with openings I0 therethrough to discharge fluid into' the bottom of the well. Toward the upper end of the valve housing and above the valve is a bushing Il extending upwardly within the lower end of the strainer and having an inner beveled seat I2 thereon,l the purpose of which will be later noted. After the liner and strainer have thus been installed in Ythe well production may enter through the strainer and flow upwardly `in the casing. When the strainer becomes clogged, however, it becomes advisable to remove thestrainer and liner from the well. Also, it may be found after the strainer has been set initially that very little oil or gas is present and the strainer and packer may thus have to be removed. In such case the device shown in the drawing is employed. I provide a drill stem having adjacent the lower end thereof a milling tool I3`and above the said milling tool an inside pipe cutter i4` and `above the pipe cutter a spear of pulling device i5. f The spear which is at the upper end of this combination of instrumentsis formed with an upper collar i6, into which the lower end of the drill stem is engaged. This collar has a threaded attachment interiorly at its lower end with a mandrel i1. Said mandrel is a tubular section of f pipe threaded toward the lower portion of its length with a coarse thread i8, said thread being a lefthand thread. At the lower 'end of the mandrel is a sealing member made up of a downwardly presented cup i9 held in position between a nut 20 above the same and a. anged collar 2i below the same. This sealing member nts closely within a barrel or cylinder '22 threaded at the 'lower end of an expanding collar 23. Between the lower end of the expanding collar 23 and the upper end of the nut 2li is a clutch member of ordinary construction which will engage on rotation in one direction but release on rotation in the opposite direction. The collar is disclosed in my co-pendingapplication Serial No. 67,787, filed March 9, 1936, and will beV readily understood.

The upper end of the expanding collar 23 .is

tapered upwardly to form a seat against which may engage pipe gripping dogs 24.y Said dogs are formed on arms 25 the upper ends of which a pull may be exerted thereon.

Below the spear and spaced the desired distance below the same is a cutting tool I4. This tool comprises a tubular housing 30 having comparatively thick walls to form a support for the cutters. 'I'he lower .end of the housing is threaded on its interior at 3| for connection with a pipe or connecting member below the same. 'I'he side.-

walls of the housing are formed with openings 32 through which the cutters 33 may slide. Said cutters are shown as rectangular in shape but having an outer tapered cutting member 34 thereon to engage and cut the pipe. Each cutter is formed with a notch on the upper surface thereof into which'engages the lower end of a spring arm 35. Said spring arm is set within an upwardly tapered recess in the outer wall of the housing and is secured therein by screws 36 or other equivalent means. 'Ihis spring tends to hold the cutter retracted inwardly away from the pipe.

On the interior of the housing 30 is an expanding member comprising a sleeve 31 tting closely within the upper portion of the housing and having a sealing ring 38 on its outer ,side to engage with the inner wall of the housing and form a vseal therewith. Adjacent the cutter block 33 the outer wall of theexpander is formed with a downwardly inclined recess 39 therein into which the cutter block may be moved as shown in Fig. 2. Below this tapered recess is a second sealing ring 40 presented vdownwardly to prevent the passage of uid upwardly around the expander. The upper end of the .expanding sleeve 31 is formed with an inwardly tapered ange 4I, which provides a seatfor a ball valve 42 which may be introduced into this position when the cutter is to be actuated.

Below the cutter is a milling tool I3 previously noted. This milling tool has a forward cutting end 43 adapted to cut away the metal at the lower ,end of the back pressure housing. It has openings 44 therein through which the llushing iluid may be discharged. This milling tool is connected by a drill collar 45 with a collar or coupling member 46. Below said coupling is an enlarged head 41 on the drill collar which has a. lower beveled shoulder 48 to engage the seat I2 in the bushing II.

In operating my device to remove the pipe from the well the first operation will be to lower the assembly as shown in the drawing downwardly into the well and apply the milling tool to mill away the metal at the lower end of the strainer. This will involve cutting away the parts of the back pressure valve, wash ring and pilot bit at the lower end and it is to be understood that various devices may be thus cut away atthe lower end of the strainer. When the milling tool has entirely cut through the lower end of the strainer and back pressure valve it will project from the lower end so as to allow uid to be pumped around the lower end of the valve housing. When in this position the shoulder 48 on .member 31. Fluid the head 41 of the ldrill collar will engage within the seat I2 inathe bushing II and prevent iluid from owing up through the interior ofthe strainer. After the fluid has been pumped around the lower end of the valve housing in this manner it is sometimes possible to withdraw the strainer and liner. 'I'his may be done by expanding the spear I5. To do this the milling tool is held fast on the bottom so as to retain the apparatus below the spear in a stationary position. The4 drill stem is then rotated in a lefthand direction to screvi'ithe mandrel I8 downwardly into the expanding collar 23 and push the pipe engaging jaws 24 against the pipe so that a pull lon the pipe may be accomplished. It it is found that the strainer is thus loosened so that it can be pulled the whole .assembly may be removed. Ordinarily however it is found that the device can not be pulled. In such case the drill stem is rotated to loosen the spear and the device is then adjusted to bring the cutter at the proper position to cut away the upper end of the liner or so much of the same as it is thought may be pulled.

When in this position the ball valve 42 is dropped downwardly and through4 the drill stem into the seat at the upper end of the expanding v pressure is then exerted on the valve and expanding member to move the same downward and extend the cutters 33 outvwardly against the liner. The drill stem will then be rotated to cut the pipe as the cutters are forced outwardly by the fluid pressure. The sleeve 31 will be forced downwardly until the cutters are projected entirely through the pipe 6 and the pipe is severed. The sleeve will then be forced downwardly until the lower end thereof contacts with the shoulder 50. Said shoulder is spaced so that when the sleeve is stopped thereby, the upper end of the `said sleeve will have passed the shoulder 52 below seal 40 and the ilushing fluid will then pass around the outside of the said sleeve and through notches 5I in the ends oi the sleeve and circulate downwardly into the well. 'I'he pumps will thus indicate when the cut has been made. When the pipe has been severed the spear -may then be engaged with the upper end thereof as has previously been described and .a pull exerted on the severed upper section of the liner. It may thus be possible to remove the upper section and go down and by making another cut gradually remove the Whole assembly.

It will be noted that if it is possible to wash the pipe loose from the walls of the hole so that the strainer may be withdrawn without cutting, the upward pull on the liner and strainer will carry with it the packer which forms a piston in the well. In such case it will be possible for fluid inside the liner and strainer to drain out the lower end through the passage cut by the milling tool. Without the cutting of this passage the lower end of the assembly would be closed in such manner that it would be dimcult to pull the same to the surface and the device would thus act as a swab and move all of the mud out the upper end of the well.

However, where an opening has thus been formed downwardly through the strainer and back pressure valve iiuid pumped around the 'lower end of the strainer and liner will be it may be pulled.

It will be noted that I have thus provided a means te loosen the pipe from the well to exert a 76 lifting eiect due to the pressure iiuid to help move the liner and packer upwardly in the wall and have provided an effective gripping device whereby a. strong pull may be exerted. It will be obvious that with my combined tool I will be able to perform all the necessary operations in removing the pipe without the necessity of removing the assembly from the well.

What is claimed as new is:

l. In a well having a casing set therein and a liner` and back pressure valve, a packer sealing between said liner and casing, metal cutting means to remove said back pressure valve and open a passage for fluid downwardly through said liner in combination with means to exert a pull on said liner and packer and a drain for liquid above said packer into said liner.

2. A pipe cutter including a tubular housing, cutter blocks slidable radially in openings in said housing, springs to hold said blocks normally retracted, a sleeve slidable longitudinally in said housing, means on said sleeve to engage and move said cutter blocks outwardly on downward movement of said sleeve, means to seal between said sleeve and said housing, above and below said cutter engaging means, and a valve actuated from the upper end of the Well to close the upper end of said sleeve whereby fluid pressure thereon will move said sleeve.

3. A pipe cutter including a tubular housing, cutter blocks slidable radially in openings in said housing, springs to hold said blocks normally retracted, a sleeve slidable longitudinally in said housing, means on said sleeve to engage and move said cutter blocks outwardly on downward movement of said sleeve, means to seal between said sleeve and said housing above and below said cutter engaging means, and means to close the upper end of said sleeve when desired so that fluid pumped downwardly through said cutter will move said sleeve.

4. A pipe vcutter including a tubular housing, cutter blocks slidable radially in openings in said housing, springs to hold said blocks .normally retracted, a sleeve slidable longitudinally in said housing, means on said sleeve to engage and move said cutter blocks outwardly on downward movement of said sleeve, means to seal between said sleeve and said housing above and below said cutter engaging means, means to close the passage through said sleeve so that fluid may be pumped downwardly to move 'said sleeve, and means to open up a by-pass around said sleeve when said sleeve is moved to its lowest position.

5. A method of removing pipe from wells equipped with liner, packer and back pressure valve including cutting a passage downwardly through said valve, circulating fluid under pressure through the lower end of said liner and upwardly against said packer, cutting said pipe below said packer, engaging the upper end of said liner and withdrawing the cut-off section thereof and said packer from the well.

6. A method of removing pipe from wells equipped with liner, packer and back pressure valve including cutting a passage downwardly through said valve, circulating uid under pressure through the lower end of Said liner, cutting said pipe below said packer, engaging the upper end of said liner and withdrawing the cut-oil? section thereof and said packer from the well and simultaneously pumping iiuid through said liner into the bottom of the well.

7. A pipe cutter including a tubular housing, cutter blocks slidable laterally in openings in said housing, a sleeve slidable longitudinally in said housing, means on said sleeve to engage and move said cutter blocks outwardly on downward movement of said sleeve, means to seal between said sleeve and said housing above and below said cutter engaging means, means to close the passage through said sleeve so that fluid may be pumped downwardly to move said sleeve and means to limit the downward movement of said sleeve, the inner wall of said housing being recessed to form a bypass for fluid from above said sleeve when said sleeve reaches its lower position.

CICERO C. BROWN. 

